Saturday, March 10, 2018

Gallivanting Tiger Sharks - new Paper!

Once again, this is evidence for the massive influence of environmental factors whereby both the coastal abundance and swimming performance of those migrating Tiger Sharks are being shown to be highest at ~22°C. Consequently, they track their optimal temperature and are thus more likely to be found in coastal areas in winter in the tropics; but towards temperate latitudes, they are more likely to be found in coastal areas in summer, see the figure at the top - and as climate change continues to heat up the oceans, those tracks are likely to shift poleward with according potential consequences for coastal communities, see the example of Sydney.

Very interesting!

Incidentally, this is very similar to what we are currently experiencing with our Bulls who have been shown to favor a temperature of ~26°C.
As the water temperature at Shark Reef has recently hovered around 29°C for a protracted period of time, the number of especially the larger Bull Sharks has been appreciably lower - and whereas we don't dispose of any strong evidence, it is only fair to speculate that they may have retreated to greater depths or even absconded to places like Kadavu where the water temperature has been significantly lowered by Gita.